Microsoft Security Bulletin MS15-076 - Important

In this article

Executive Summary

This security update resolves a vulnerability in Microsoft Windows. The vulnerability, which exists in Windows Remote Procedure Call (RPC) authentication, could allow elevation of privilege if an attacker logs on to an affected system and runs a specially crafted application. An attacker who successfully exploited this vulnerability could take complete control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

This security update is rated Important for all supported releases of Windows. For more information, see the Affected Software section.

The security update addresses the vulnerability by improving how Windows Remote Procedure Call (RPC) handles authentication checks to preclude redirection. For more information about the vulnerability, see the Vulnerability Information section.

Affected Software

The following software versions or editions are affected. Versions or editions that are not listed are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, see Microsoft Support Lifecycle.

*The Updates Replaced column shows only the latest update in a chain of superseded updates. For a comprehensive list of updates replaced, go to the Microsoft Update Catalog, search for the update KB number, and then view update details (updates replaced information is on the Package Details tab).

Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the July bulletin summary.

Vulnerability Information

Windows RPC Elevation of Privilege Vulnerability - CVE-2015-2370

An elevation of privilege vulnerability exists in the Microsoft Remote Procedure Call (RPC) that could allow an attacker to elevate privileges on a targeted system. The vulnerability is caused when Windows RPC inadvertently allows DCE/RPC connection reflection.

An attacker who successfully exploited this vulnerability could take complete control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to elevate privileges.

The update addresses the vulnerability by improving how Windows RPC handles authentication checks to preclude redirection.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was issued, Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Security Update Deployment

Acknowledgments

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information.

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.